ms = 2 kg = 2000 g, c% = 10%
stim ca c% = mdx100/ms
=> md = msxc%/100 = 2000x10/100
= 200 g CuSO4
M.CuSO4 = 64+32+4x16 = 160 g/mol
M.H2O = 2+16 = 18 g/mol
stim ca nr.moli(n) = masa/M
=> n.CuSO4 = 200/160 = 1,25 moli
din ms => m.apa = ms - md
= 2000-200 = 1800 g
=> n.H2O = 1800/18 = 100 moli